nmbd_browsesync.c

来自「samba-3.0.22.tar.gz 编译smb服务器的源码」· C语言 代码 · 共 680 行 · 第 1/2 页

/* 
   Unix SMB/CIFS implementation.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   Copyright (C) Jeremy Allison 1994-2003
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
*/

#include "includes.h"

/* This is our local master browser list database. */
extern ubi_dlList lmb_browserlist[];

/****************************************************************************
As a domain master browser, do a sync with a local master browser.
**************************************************************************/

static void sync_with_lmb(struct browse_cache_record *browc)
{                     
	struct work_record *work;

	if( !(work = find_workgroup_on_subnet(unicast_subnet, browc->work_group)) ) {
		if( DEBUGLVL( 0 ) ) {
			dbgtext( "sync_with_lmb:\n" );
			dbgtext( "Failed to get a workgroup for a local master browser " );
			dbgtext( "cache entry workgroup " );
			dbgtext( "%s, server %s\n", browc->work_group, browc->lmb_name );
		}
		return;
	}

	/* We should only be doing this if we are a domain master browser for
		the given workgroup. Ensure this is so. */

	if(!AM_DOMAIN_MASTER_BROWSER(work)) {
		if( DEBUGLVL( 0 ) ) {
			dbgtext( "sync_with_lmb:\n" );
			dbgtext( "We are trying to sync with a local master browser " );
			dbgtext( "%s for workgroup %s\n", browc->lmb_name, browc->work_group );
			dbgtext( "and we are not a domain master browser on this workgroup.\n" );
			dbgtext( "Error!\n" );
		}
		return;
	}

	if( DEBUGLVL( 2 ) ) {
		dbgtext( "sync_with_lmb:\n" );
		dbgtext( "Initiating sync with local master browser " );
		dbgtext( "%s<0x20> at IP %s ", browc->lmb_name, inet_ntoa(browc->ip) );
		dbgtext( "for workgroup %s\n", browc->work_group );
	}

	sync_browse_lists(work, browc->lmb_name, 0x20, browc->ip, True, True);

	browc->sync_time += (CHECK_TIME_DMB_TO_LMB_SYNC * 60);
}

/****************************************************************************
Sync or expire any local master browsers.
**************************************************************************/

void dmb_expire_and_sync_browser_lists(time_t t)
{
	static time_t last_run = 0;
	struct browse_cache_record *browc;

	/* Only do this every 20 seconds. */  
	if (t - last_run < 20) 
		return;

	last_run = t;

	expire_lmb_browsers(t);

	for( browc = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
			browc;
			browc = (struct browse_cache_record *)ubi_dlNext( browc ) ) {
		if (browc->sync_time < t)
			sync_with_lmb(browc);
	}
}

/****************************************************************************
As a local master browser, send an announce packet to the domain master browser.
**************************************************************************/

static void announce_local_master_browser_to_domain_master_browser( struct work_record *work)
{
	pstring outbuf;
	unstring myname;
	unstring dmb_name;
	char *p;

	if(ismyip(work->dmb_addr)) {
		if( DEBUGLVL( 2 ) ) {
			dbgtext( "announce_local_master_browser_to_domain_master_browser:\n" );
			dbgtext( "We are both a domain and a local master browser for " );
			dbgtext( "workgroup %s.  ", work->work_group );
			dbgtext( "Do not announce to ourselves.\n" );
		}
		return;
	}

	memset(outbuf,'\0',sizeof(outbuf));
	p = outbuf;
	SCVAL(p,0,ANN_MasterAnnouncement);
	p++;

	unstrcpy(myname, global_myname());
	strupper_m(myname);
	myname[15]='\0';
	/* The call below does CH_UNIX -> CH_DOS conversion. JRA */
	push_pstring_base(p, myname, outbuf);

	p = skip_string(p,1);

	if( DEBUGLVL( 4 ) ) {
		dbgtext( "announce_local_master_browser_to_domain_master_browser:\n" );
		dbgtext( "Sending local master announce to " );
		dbgtext( "%s for workgroup %s.\n", nmb_namestr(&work->dmb_name),
					work->work_group );
	}

	/* Target name for send_mailslot must be in UNIX charset. */
	pull_ascii_nstring(dmb_name, sizeof(dmb_name), work->dmb_name.name);
	send_mailslot(True, BROWSE_MAILSLOT, outbuf,PTR_DIFF(p,outbuf),
		global_myname(), 0x0, dmb_name, 0x0, 
		work->dmb_addr, FIRST_SUBNET->myip, DGRAM_PORT);
}

/****************************************************************************
As a local master browser, do a sync with a domain master browser.
**************************************************************************/

static void sync_with_dmb(struct work_record *work)
{
	unstring dmb_name;

	if( DEBUGLVL( 2 ) ) {
		dbgtext( "sync_with_dmb:\n" );
		dbgtext( "Initiating sync with domain master browser " );
		dbgtext( "%s ", nmb_namestr(&work->dmb_name) );
		dbgtext( "at IP %s ", inet_ntoa(work->dmb_addr) );
		dbgtext( "for workgroup %s\n", work->work_group );
	}

	pull_ascii_nstring(dmb_name, sizeof(dmb_name), work->dmb_name.name);
	sync_browse_lists(work, dmb_name, work->dmb_name.name_type, 
		work->dmb_addr, False, True);
}

/****************************************************************************
  Function called when a node status query to a domain master browser IP succeeds.
****************************************************************************/

static void domain_master_node_status_success(struct subnet_record *subrec,
                                              struct userdata_struct *userdata,
                                              struct res_rec *answers,
                                              struct in_addr from_ip)
{
	struct work_record *work = find_workgroup_on_subnet( subrec, userdata->data);

	if( work == NULL ) {
		if( DEBUGLVL( 0 ) ) {
			dbgtext( "domain_master_node_status_success:\n" );
			dbgtext( "Unable to find workgroup " );
			dbgtext( "%s on subnet %s.\n", userdata->data, subrec->subnet_name );
		}
		return;
	}

	if( DEBUGLVL( 3 ) ) {
		dbgtext( "domain_master_node_status_success:\n" );
		dbgtext( "Success in node status for workgroup " );
		dbgtext( "%s from ip %s\n", work->work_group, inet_ntoa(from_ip) );
	}

  /* Go through the list of names found at answers->rdata and look for
     the first SERVER<0x20> name. */

	if(answers->rdata != NULL) {
		char *p = answers->rdata;
		int numnames = CVAL(p, 0);

		p += 1;

		while (numnames--) {
			unstring qname;
			uint16 nb_flags;
			int name_type;

			pull_ascii_nstring(qname, sizeof(qname), p);
			name_type = CVAL(p,15);
			nb_flags = get_nb_flags(&p[16]);
			trim_char(qname,'\0',' ');

			p += 18;

			if(!(nb_flags & NB_GROUP) && (name_type == 0x20)) {
				struct nmb_name nmbname;

				make_nmb_name(&nmbname, qname, name_type);

				/* Copy the dmb name and IP address
					into the workgroup struct. */

				work->dmb_name = nmbname;
				putip((char *)&work->dmb_addr, &from_ip);

				/* Do the local master browser announcement to the domain
					master browser name and IP. */
				announce_local_master_browser_to_domain_master_browser( work );

				/* Now synchronise lists with the domain master browser. */
				sync_with_dmb(work);
				break;
			}
		}
	} else if( DEBUGLVL( 0 ) ) {
		dbgtext( "domain_master_node_status_success:\n" );
		dbgtext( "Failed to find a SERVER<0x20> name in reply from IP " );
		dbgtext( "%s.\n", inet_ntoa(from_ip) );
	}
}

/****************************************************************************
  Function called when a node status query to a domain master browser IP fails.
****************************************************************************/

static void domain_master_node_status_fail(struct subnet_record *subrec,
                       struct response_record *rrec)
{
	struct userdata_struct *userdata = rrec->userdata;

	if( DEBUGLVL( 0 ) ) {
		dbgtext( "domain_master_node_status_fail:\n" );
		dbgtext( "Doing a node status request to the domain master browser\n" );
		dbgtext( "for workgroup %s ", userdata ? userdata->data : "NULL" );
		dbgtext( "at IP %s failed.\n", inet_ntoa(rrec->packet->ip) );
		dbgtext( "Cannot sync browser lists.\n" );
	}
}

/****************************************************************************
  Function called when a query for a WORKGROUP<1b> name succeeds.
****************************************************************************/

static void find_domain_master_name_query_success(struct subnet_record *subrec,
                        struct userdata_struct *userdata_in,
                        struct nmb_name *q_name, struct in_addr answer_ip, struct res_rec *rrec)
{
	/* 
	 * Unfortunately, finding the IP address of the Domain Master Browser,
	 * as we have here, is not enough. We need to now do a sync to the
	 * SERVERNAME<0x20> NetBIOS name, as only recent NT servers will
	 * respond to the SMBSERVER name. To get this name from IP
	 * address we do a Node status request, and look for the first
	 * NAME<0x20> in the response, and take that as the server name.
	 * We also keep a cache of the Domain Master Browser name for this
	 * workgroup in the Workgroup struct, so that if the same IP addess
	 * is returned every time, we don't need to do the node status
	 * request.
	 */

	struct work_record *work;
	struct nmb_name nmbname;
	struct userdata_struct *userdata;
	size_t size = sizeof(struct userdata_struct) + sizeof(fstring)+1;
	unstring qname;

	pull_ascii_nstring(qname, sizeof(qname), q_name->name);
	if( !(work = find_workgroup_on_subnet(subrec, qname)) ) {
		if( DEBUGLVL( 0 ) ) {
			dbgtext( "find_domain_master_name_query_success:\n" );
			dbgtext( "Failed to find workgroup %s\n", qname);
		}
	return;
  }

  /* First check if we already have a dmb for this workgroup. */

	if(!is_zero_ip(work->dmb_addr) && ip_equal(work->dmb_addr, answer_ip)) {
		/* Do the local master browser announcement to the domain
			master browser name and IP. */
		announce_local_master_browser_to_domain_master_browser( work );

		/* Now synchronise lists with the domain master browser. */
		sync_with_dmb(work);
		return;
	} else {
		zero_ip(&work->dmb_addr);
	}

	/* Now initiate the node status request. */

	/* We used to use the name "*",0x0 here, but some Windows
	 * servers don't answer that name. However we *know* they
	 * have the name workgroup#1b (as we just looked it up).
	 * So do the node status request on this name instead.
	 * Found at LBL labs. JRA.
	 */

	make_nmb_name(&nmbname,work->work_group,0x1b);

	/* Put the workgroup name into the userdata so we know
	 what workgroup we're talking to when the reply comes
	 back. */

	/* Setup the userdata_struct - this is copied so we can use
	a stack variable for this. */

	if((userdata = (struct userdata_struct *)SMB_MALLOC(size)) == NULL) {
		DEBUG(0, ("find_domain_master_name_query_success: malloc fail.\n"));
		return;
	}

	userdata->copy_fn = NULL;
	userdata->free_fn = NULL;
	userdata->userdata_len = strlen(work->work_group)+1;
	overmalloc_safe_strcpy(userdata->data, work->work_group, size - sizeof(*userdata) - 1);

	node_status( subrec, &nmbname, answer_ip, 
		domain_master_node_status_success,
		domain_master_node_status_fail,
		userdata);